//websocket客户端
var websocket = null;
     var ws = null;
     ws = "ws://localhost:8080/WithMe/server";
     //判断当前浏览器是否支持WebSocket
     if ('WebSocket' in window) {	 
         websocket = new WebSocket(ws);
     	 alert(ws);
     }
     else {
         alert('当前浏览器 Not support websocket');
     };
 
     //连接发生错误的回调方法
     websocket.onerror = function () {
         setMessageInnerHTML("WebSocket连接发生错误");
     };
 
     //连接成功建立的回调方法
     websocket.onopen = function () {
         setMessageInnerHTML("WebSocket连接成功");
     };
 
     //接收到消息的回调方法
     websocket.onmessage = function (event) {
         setMessageInnerHTML(event.data);
     };
 
     //连接关闭的回调方法
     websocket.onclose = function () {
         setMessageInnerHTML("WebSocket连接关闭");
     };
 
     //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
     window.onbeforeunload = function () {
         closeWebSocket();
     };
 
     //将消息显示在网页上
     function setMessageInnerHTML(innerHTML) {
         document.getElementById('message').innerHTML += innerHTML + '<br/>';
     }
 
     //关闭WebSocket连接
     function closeWebSocket() {
         websocket.close();
     }
 
     //发送消息
     function send() {
         var message = document.getElementById('text').value;
         websocket.send(message);
     }